/* Matematik Vakti Z-Kitap — yüzen araç kutusu.
   RENKLER: uygulamanın bütün renkleri bu bloktan gelir; değiştirmek için sadece burayı düzenleyin. */
:root {
  --accent: #0f7480;               /* PDF Tahtası: petrol yeşili (Z-Kitap mavisinden ayrı) */
  --accent-2: #22a3a6;
  --accent-dark: #17393d;
  --accent-soft: #e0f2f1;
  --accent-fg: #ffffff;
  --bg: #e8f1f0;
  --panel: #f5fafa;
  --fg: #1d2b38;
  --muted: #5b6b7b;
  --line: #cde0de;
  --danger: #b3372a;
  --primary-color: var(--accent);  /* eski kodun kullandığı ad (yükleme çubuğu) */
  --background-color: #525659;     /* kitap arka planı */
  --toolbar-width: 256px;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  height: 100vh;
  background-color: var(--bg);
  color: var(--fg);
  overflow: hidden;
}

/* --- YÜZEN MENÜ (Araç Kutusu) --- */
#toolbar {
  position: fixed;
  left: 12px;                      /* gerçek konumu script verir ve hatırlar */
  top: 12px;
  z-index: 1000;
  width: var(--toolbar-width);
  max-height: calc(100vh - 16px);
  display: flex;
  flex-direction: column;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: 0 10px 30px rgba(10, 30, 36, 0.28);
  overflow: hidden;
}
#toolbar[hidden] { display: none; }
.tb-head {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 6px 6px 12px;
  background: var(--accent);
  color: var(--accent-fg);
  cursor: grab;
  touch-action: none;              /* dokunmatikte sürükleme sayfayı kaydırmasın */
  user-select: none;
}
.tb-head.dragging { cursor: grabbing; }
.tb-grip { opacity: 0.75; }
.tb-title { flex: 1; font-size: 0.85rem; font-weight: 700; letter-spacing: 0.02em; }
#toolbar .tb-head-btn {
  width: 34px; min-height: 30px; height: 30px; flex: 0 0 auto; justify-content: center; padding: 0;
  background: rgba(255,255,255,0.14); border: 1px solid rgba(255,255,255,0.35); color: #fff;
}
#toolbar .tb-head-btn:hover { background: rgba(255,255,255,0.28); border-color: #fff; }
.tb-body {
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  scrollbar-width: thin;
  padding: 10px 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

/* Küçültülmüş hali: yuvarlak düğme */
#tb-bubble {
  position: fixed;
  left: 12px;
  top: 12px;
  z-index: 1000;
  width: 64px;
  height: 64px;
  border-radius: 50%;
  border: 3px solid #fff;
  background: var(--accent);
  color: #fff;
  box-shadow: 0 6px 18px rgba(10, 30, 36, 0.35);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  font: inherit;
  font-size: 0.62rem;
  font-weight: 700;
  cursor: grab;
  touch-action: none;
  user-select: none;
}
#tb-bubble i { font-size: 1.3rem; }
#tb-bubble[hidden] { display: none; }

/* Katlanabilir bölüm başlıkları */
.tool-group .sec-head {
  display: flex;
  align-items: center;
  cursor: pointer;
  padding: 2px 0;
  user-select: none;
}
.tool-group .sec-arrow { margin-left: auto; font-size: 0.75em; transition: transform 0.2s ease; }
.tool-group.folded .sec-arrow { transform: rotate(-90deg); }
.tool-group.folded .sec-body { display: none; }
.sec-body { display: flex; flex-direction: column; gap: 5px; }
.tool-group.folded { padding-bottom: 2px; border-bottom: 1px dashed var(--line); }
.tool-group { display: flex; flex-direction: column; gap: 5px; }
.tool-group h3 {
  margin: 0 0 1px;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
}
.tool-group h4 {
  margin: 6px 0 0;
  font-size: 0.66rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
}

/* Düğmeler */
#toolbar button {
  width: 100%;
  min-height: 36px;
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--fg);
  font: inherit;
  font-size: 0.86rem;
  text-align: left;
  text-decoration: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: background-color 0.15s, border-color 0.15s;
}
#toolbar button i.fa-fw { width: 1.15em; text-align: center; color: var(--accent); }
#toolbar button:hover { background: var(--accent-soft); border-color: var(--accent); }
#toolbar button.active { background: var(--accent); border-color: var(--accent); color: var(--accent-fg); font-weight: 600; }
#toolbar button.active i.fa-fw { color: var(--accent-fg); }
#toolbar button:disabled { opacity: 0.45; cursor: default; background: #fff; border-color: var(--line); }
#toolbar button.danger-btn, #toolbar button.danger-btn i.fa-fw { color: var(--danger); }
button:focus-visible, a:focus-visible, input:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* Satırlar ve ızgaralar */
.row { display: flex; align-items: center; gap: 5px; }
.row.two > button { flex: 1 1 0; min-width: 0; justify-content: center; padding-left: 6px; padding-right: 6px; white-space: nowrap; }
.tool-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 5px; }
.tool-grid > * { min-width: 0; }
.tool-grid > .submenu { grid-column: 1 / -1; }
#toolbar .icon-btn { width: 36px; flex: 0 0 auto; justify-content: center; padding: 0; }
.page-info { flex: 1; text-align: center; font-variant-numeric: tabular-nums; font-size: 0.9rem; }
#page-input {
  flex: 1; min-width: 0; height: 36px; padding: 0 8px;
  border: 1px solid var(--line); border-radius: 8px; font: inherit; font-size: 0.86rem; text-align: center;
}
#toolbar .go-btn { width: 56px; flex: 0 0 auto; justify-content: center; background: var(--accent); border-color: var(--accent); color: var(--accent-fg); }
#toolbar .go-btn:disabled { background: #fff; color: var(--fg); }

/* Açılır bölümler */
.submenu { display: none; }
.submenu-trigger.active + .submenu { display: flex; flex-direction: column; gap: 5px; padding: 6px 0 4px 8px; border-left: 3px solid var(--accent-soft); }
.submenu-arrow { margin-left: auto; font-size: 0.75em; color: var(--muted); transition: transform 0.25s ease; }
.submenu-trigger.active .submenu-arrow { transform: rotate(180deg); }
#toolbar .submenu-trigger.active { background: var(--accent-soft); border-color: var(--accent); color: var(--fg); font-weight: 600; }
#toolbar .submenu-trigger.active i.fa-fw { color: var(--accent); }
#toolbar .submenu-trigger.has-shape { border-color: var(--accent); box-shadow: inset 3px 0 0 var(--accent); }
.toc-list { max-height: 260px; overflow-y: auto; }
#toolbar .toc-list button, #book-selection-submenu button { font-size: 0.82rem; min-height: 34px; }
#book-selection-submenu button.current { border-color: var(--accent); font-weight: 600; }

/* Şekil ızgarası */
.submenu-trigger.active + .shape-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 5px; padding: 6px 0 2px; border-left: none; }
#toolbar .shape-btn { flex-direction: column; justify-content: center; gap: 2px; min-height: 52px; padding: 6px 4px; font-size: 0.74rem; text-align: center; }
.shape-btn svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linejoin: round; stroke-linecap: round; }
.shape-btn svg .f { fill: currentColor; }

/* Renk ve kalınlık */
.color-palette { display: grid; grid-template-columns: repeat(5, 1fr); gap: 6px; justify-items: center; }
.color-swatch {
  width: 30px; height: 30px; border-radius: 50%; cursor: pointer;
  border: 2px solid #fff; box-shadow: 0 0 0 1px var(--line);
}
.color-swatch.selected { box-shadow: 0 0 0 3px var(--fg); }
.thickness-row label { font-size: 0.82rem; color: var(--muted); }
#thickness-slider { flex: 1; min-width: 0; accent-color: var(--accent); }
#thickness-value { width: 20px; text-align: right; font-variant-numeric: tabular-nums; font-size: 0.85rem; }

.copyright-notice { margin-top: auto; padding-top: 8px; border-top: 1px solid var(--line); text-align: center; font-size: 0.75rem; color: var(--muted); }
.copyright-notice a { color: inherit; text-decoration: none; }
.copyright-notice a:hover { text-decoration: underline; }

/* --- KİTAP ALANI --- */
#pdf-container {
  position: fixed;
  inset: 0;                        /* kitap bütün ekranı kullanır; menü üstünde yüzer */
  background: var(--background-color);
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: auto;
  padding: 25px;
}
#main-canvas-wrapper {
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.4);
  margin: auto;
  display: flex;
  justify-content: center;
}

/* --- Hızlı sayfa geçiş çubuğu --- */
#page-nav {
  position: fixed;
  bottom: 18px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 900;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px;
  background: rgba(20, 37, 43, 0.85);
  border-radius: 40px;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.35);
  color: #fff;
  font-size: 1rem;
  font-variant-numeric: tabular-nums;
}
#page-nav[hidden] { display: none; }
#page-nav button {
  width: 52px; height: 52px;
  border: none; border-radius: 50%;
  background: rgba(255, 255, 255, 0.12);
  color: #fff; font-size: 1.2rem; cursor: pointer;
}
#page-nav button:hover { background: rgba(255, 255, 255, 0.25); }
#page-nav button:disabled { opacity: 0.3; cursor: default; }
#page-nav .nav-scroll { background: rgba(255, 255, 255, 0.06); border: 1px solid rgba(255, 255, 255, 0.25); }
#nav-label { min-width: 84px; text-align: center; }

/* İki sütunlu araç düğmeleri tek satırda kalsın */
.tool-grid > button { padding-left: 8px; padding-right: 6px; gap: 6px; white-space: nowrap; }


/* 1080p altı ekranlarda (ör. 1600×900, 1366×768) menü sıkışsın, kaydırma gerekmesin */
@media (max-height: 960px) {
  .tb-body { gap: 6px; padding-top: 6px; padding-bottom: 6px; }
  .tool-group { gap: 3px; }
  #toolbar button { min-height: 30px; padding-top: 3px; padding-bottom: 3px; font-size: 0.82rem; }
  #toolbar .icon-btn, #toolbar .go-btn { min-height: 30px; }
  #page-input { height: 30px; }
  .color-swatch { width: 24px; height: 24px; }
  .color-palette { gap: 4px; }
  .tool-group h3 { font-size: 0.64rem; }
  .copyright-notice { padding-top: 4px; }
}


/* =========================================================
   DÜZEN: sade, iki sütunlu yazılı düğmeler (Matematik Vakti renkleriyle)
   ========================================================= */
#toolbar { border-radius: 16px; border: none; box-shadow: 0 16px 36px rgba(20, 40, 60, 0.28), 0 0 0 1px var(--line); }
.tb-head { background: linear-gradient(135deg, var(--accent-dark), var(--accent-2)); padding: 7px 7px 7px 10px; }
.tb-grip { display: none; }
.tb-title { display: flex; align-items: center; font-size: 0.88rem; }
.tb-title::before {                                   /* küçültülmüş haldeki alet çantası ikonu */
  content: "\f1c1"; font-family: "Font Awesome 6 Free"; font-weight: 900; font-size: 0.8rem;
  display: inline-grid; place-items: center; width: 24px; height: 24px; margin-right: 8px;
  border-radius: 7px; background: #fff; color: var(--accent);
}
#toolbar .tool-grid > button svg { width: 18px; height: 18px; flex: 0 0 auto; fill: none; stroke: var(--accent); stroke-width: 1.9; stroke-linejoin: round; stroke-linecap: round; }
#toolbar .tool-grid > button.active svg { stroke: var(--accent-fg); }
.sec-head::before { font-family: "Font Awesome 6 Free"; font-weight: 900; margin-right: 6px; color: var(--accent); }
[data-sec=kitap] .sec-head::before { content: "\f02d"; }
[data-sec=gorunum] .sec-head::before { content: "\f06e"; }
[data-sec=araclar] .sec-head::before { content: "\f6e3"; }
[data-sec=renk] .sec-head::before { content: "\f53f"; }
[data-sec=cizimler] .sec-head::before { content: "\f1fc"; }
#tb-bubble { background: linear-gradient(135deg, var(--accent-dark), var(--accent)); }
#page-nav { background: rgba(23, 57, 61, 0.92); }

/* =========================================================
   CETVEL VE GÖNYE (kitap sayfasının üstünde)
   ========================================================= */
.inst-layer { position: absolute; left: 0; top: 0; pointer-events: none; }
.inst-tip {
  position: fixed; z-index: 3000; pointer-events: none;
  background: var(--accent-dark); color: #fff; font: 600 14px ui-monospace, Consolas, monospace;
  padding: 5px 9px; border-radius: 7px; box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
}
.inst-tip[hidden] { display: none; }

/* Cetvel/Gönye açık: araç seçimiyle karışmasın diye farklı vurgu (açık zemin + kalın çerçeve) */
#toolbar .tool-grid > button.inst-btn.active { background: var(--accent-soft); color: var(--accent); border: 2px solid var(--accent); box-shadow: none; font-weight: 700; }
#toolbar .tool-grid > button.inst-btn.active svg { stroke: var(--accent); }

/* Alt çubuktaki sayfa numarası kutusu */
.nav-page { display: flex; align-items: center; gap: 6px; padding: 0 4px; cursor: text; }
#page-input {
  width: 64px; height: 40px; padding: 0 4px; border: 1.5px solid rgba(255, 255, 255, 0.35); border-radius: 10px;
  background: rgba(255, 255, 255, 0.12); color: #fff; font: inherit; font-size: 1.05rem; font-weight: 700;
  flex: none; text-align: center; font-variant-numeric: tabular-nums; -moz-appearance: textfield;
}
#page-input::-webkit-outer-spin-button, #page-input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
#page-input:focus { outline: none; background: #fff; color: var(--fg); border-color: #fff; }
#page-input:disabled { opacity: 0.5; }
#nav-label { min-width: 0; color: rgba(255, 255, 255, 0.85); }

/* Şekiller paneli (Araç Kutusu'nun yanında) */
.shape-fly {
  position: fixed; z-index: 1100; width: 236px;
  display: grid; grid-template-columns: 1fr 1fr; gap: 6px; padding: 10px;
  background: var(--panel); border-radius: 14px;
  box-shadow: 0 14px 32px rgba(20, 40, 60, 0.28), 0 0 0 1px var(--line);
}
.shape-fly[hidden] { display: none; }
.shape-fly .shape-btn {
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 3px;
  min-height: 56px; padding: 6px 4px; border: 1px solid var(--line); border-radius: 10px;
  background: #fff; color: var(--fg); font: inherit; font-size: 0.78rem; cursor: pointer;
}
.shape-fly .shape-btn svg { width: 24px; height: 24px; fill: none; stroke: var(--accent); stroke-width: 1.8; stroke-linejoin: round; stroke-linecap: round; }
.shape-fly .shape-btn svg .f { fill: var(--accent); }
.shape-fly .shape-btn:hover { background: var(--accent-soft); border-color: var(--accent); }
.shape-fly .shape-btn.active { background: var(--accent); border-color: var(--accent); color: var(--accent-fg); font-weight: 600; }
.shape-fly .shape-btn.active svg { stroke: var(--accent-fg); }
.shape-fly .shape-btn.active svg .f { fill: var(--accent-fg); }
#toolbar .fly-arrow { margin-left: auto; font-size: 0.7em; color: var(--muted); }
#toolbar #shapes-btn.open, #toolbar #book-btn.open { background: var(--accent-soft); border-color: var(--accent); }

#toolbar .tool-grid > button.inst-btn.active i.fa-fw { color: var(--accent); }

/* Kitap Seç paneli (Araç Kutusu'nun yanında) */
.book-fly {
  position: fixed; z-index: 1100; width: 290px; max-height: min(70vh, 560px); overflow-y: auto;
  padding: 10px; background: var(--panel); border-radius: 14px;
  box-shadow: 0 14px 32px rgba(20, 40, 60, 0.28), 0 0 0 1px var(--line);
}
.book-fly[hidden] { display: none; }
.book-fly .fly-title { font-size: 0.72rem; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); padding: 2px 4px 8px; }
.book-fly #book-selection-submenu { display: flex; flex-direction: column; gap: 5px; }
.book-fly .tool-btn {
  display: flex; align-items: center; gap: 8px; width: 100%; min-height: 38px; padding: 7px 10px;
  border: 1px solid var(--line); border-radius: 10px; background: #fff; color: var(--fg);
  font: inherit; font-size: 0.85rem; text-align: left; cursor: pointer;
}
.book-fly .tool-btn i { color: var(--accent); }
.book-fly .tool-btn:hover { background: var(--accent-soft); border-color: var(--accent); }
.book-fly .tool-btn.current { border-color: var(--accent); box-shadow: inset 3px 0 0 var(--accent); font-weight: 600; }

/* Beyaz tahta zemini seçimi */
.wb-bg { display: grid; grid-template-columns: repeat(3, 1fr); gap: 5px; margin-top: 6px; }
.wb-bg[hidden] { display: none; }
#toolbar .wb-bg button {
  display: flex; flex-direction: column; align-items: center; gap: 3px; min-height: 0; padding: 6px 2px;
  font-size: 0.74rem; justify-content: center;
}
.wb-bg .sw { width: 30px; height: 20px; border-radius: 4px; border: 1px solid var(--line); background-color: #fff; }
.wb-bg .sw.dots { background-image: radial-gradient(circle, #8fa5bb 1.2px, transparent 1.4px); background-size: 6px 6px; background-position: 3px 3px; }
.wb-bg .sw.grid { background-image: linear-gradient(#c3d3e3 1px, transparent 1px), linear-gradient(90deg, #c3d3e3 1px, transparent 1px); background-size: 6px 6px; }
#toolbar .wb-bg button.active { background: var(--accent-soft); border-color: var(--accent); color: var(--fg); font-weight: 600; }
#toolbar #shade-btn.active, #toolbar #spot-btn.active { background: var(--accent-soft); border-color: var(--accent); color: var(--fg); font-weight: 600; }
#toolbar #shade-btn.active i, #toolbar #spot-btn.active i { color: var(--accent); }

/* Perde */
.shade {
  position: fixed; z-index: 880; touch-action: none;
  background: repeating-linear-gradient(90deg, rgba(255,255,255,0.025) 0 22px, rgba(0,0,0,0.04) 22px 44px), linear-gradient(180deg, #2c4359, #1f3142);
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.08), 0 10px 34px rgba(0, 0, 0, 0.4);
}
.shade[hidden], .spot-layer[hidden] { display: none; }
.sh-h {
  position: absolute; display: flex; align-items: center; justify-content: center;
  width: 84px; height: 28px; border: 0; border-radius: 14px; padding: 0;
  background: #fff; box-shadow: 0 2px 8px rgba(0, 0, 0, 0.35); cursor: ns-resize; touch-action: none;
}
.sh-h i { width: 34px; height: 9px; border-top: 2px solid var(--accent); border-bottom: 2px solid var(--accent); }
.sh-h.v { width: 28px; height: 84px; cursor: ew-resize; }
.sh-h.v i { width: 9px; height: 34px; border: 0; border-left: 2px solid var(--accent); border-right: 2px solid var(--accent); }
.sh-h[data-e="t"] { top: 10px; left: 50%; transform: translateX(-50%); }
.sh-h[data-e="b"] { bottom: 10px; left: 50%; transform: translateX(-50%); }
.sh-h[data-e="l"] { left: 10px; top: 50%; transform: translateY(-50%); }
.sh-h[data-e="r"] { right: 10px; top: 50%; transform: translateY(-50%); }
.st-close {
  position: absolute; top: 10px; right: 10px; width: 38px; height: 38px; border-radius: 50%;
  border: 0; background: rgba(255, 255, 255, 0.16); color: #fff; font-size: 1rem; cursor: pointer;
}
.st-close:hover { background: rgba(255, 255, 255, 0.3); }

/* Spot ışığı */
.spot-layer { position: fixed; inset: 0; z-index: 880; overflow: hidden; touch-action: none; cursor: pointer; }
.spot-hole {
  position: absolute; border-radius: 50%; cursor: move; touch-action: none;
  box-shadow: 0 0 0 300vmax rgba(12, 22, 32, 0.86), inset 0 0 0 3px rgba(255, 255, 255, 0.8);
}
.spot-size, .spot-close {
  position: absolute; transform: translate(-50%, -50%); width: 38px; height: 38px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center; touch-action: none;
}
.spot-size { background: var(--accent); color: #fff; border: 2px solid #fff; cursor: nwse-resize; box-shadow: 0 2px 8px rgba(0, 0, 0, 0.4); }
.spot-close { top: auto; right: auto; background: rgba(255, 255, 255, 0.2); }

/* Büyütülmüşken alttaki çubukta: görünüm (Odak / Kâğıt) ve Tam Sayfa */
.nav-zoom { display: flex; align-items: center; gap: 6px; padding-left: 8px; margin-left: 2px; border-left: 1px solid rgba(255, 255, 255, 0.25); }
.nav-zoom[hidden] { display: none; }
#page-nav button.nav-pill { width: auto; height: 52px; padding: 0 16px; border-radius: 26px; display: flex; align-items: center; gap: 8px; font-size: 0.95rem; font-weight: 600; }
#page-nav button#nav-zoom-exit { background: var(--accent); }
#page-nav button#nav-zoom-exit:hover { background: var(--accent-2); }

/* Çizimler: "Sayfayı Temizle" ve "Kitabı Temizle" yan yana sığsın */
#toolbar .row.two > #clear-all { flex: 1.15 1 0; gap: 5px; }